Lead-containing copper alloys such as, typically, CAC603 (a Cu—Sn—Pb-based copper alloy) have been used for sliding members including a bearing material. In all of the lead-containing copper alloys, lead contributes to sliding performance. However, for fulfilling such a social demand that the amount of lead to be used should be reduced, various types of copper alloys for sliding materials each of which uses a reduced amount of lead have been studied.
For example, Patent document 1 discloses a sliding member produced using Cu which may be partly substituted by Sn or Zn as a matrix material and an alloy composed of any one of Fe, Ni and Co, and Mo and S as a low-friction alloy and by performing sintering of these materials. In the sliding member, an MoS2 phase contributes to a reduction in frictional coefficient and the inhibition of the generation of MoS2 by iron sulfide can be prevented by substituting a part of Fe by Mi or Co.